LangRef.rst

information about the behavior of the program after unwinding happens,
as its first non-PHI instruction. The restrictions on the
"``landingpad``" instruction's tightly couples it to the "``invoke``"
instruction, so that the important information contained within the
"``landingpad``" instruction can't be lost through normal code motion.

Arguments:
""""""""""

This instruction requires several arguments:

#. The optional "cconv" marker indicates which :ref:`calling
   convention <callingconv>` the call should use. If none is
   specified, the call defaults to using C calling conventions.
#. The optional :ref:`Parameter Attributes <paramattrs>` list for return
   values. Only '``zeroext``', '``signext``', and '``inreg``' attributes
   are valid here.
#. '``ptr to function ty``': shall be the signature of the pointer to
   function value being invoked. In most cases, this is a direct
   function invocation, but indirect ``invoke``'s are just as possible,
   branching off an arbitrary pointer to function value.
#. '``function ptr val``': An LLVM value containing a pointer to a
   function to be invoked.
#. '``function args``': argument list whose types match the function
   signature argument types and parameter attributes. All arguments must
   be of :ref:`first class <t_firstclass>` type. If the function signature
   indicates the function accepts a variable number of arguments, the
   extra arguments can be specified.
#. '``normal label``': the label reached when the called function
   executes a '``ret``' instruction.
#. '``exception label``': the label reached when a callee returns via
   the :ref:`resume <i_resume>` instruction or other exception handling
   mechanism.
#. The optional :ref:`function attributes <fnattrs>` list. Only
   '``noreturn``', '``nounwind``', '``readonly``' and '``readnone``'
   attributes are valid here.

Semantics:
""""""""""

This instruction is designed to operate as a standard '``call``'
instruction in most regards. The primary difference is that it
establishes an association with a label, which is used by the runtime
library to unwind the stack.

This instruction is used in languages with destructors to ensure that
proper cleanup is performed in the case of either a ``longjmp`` or a
thrown exception. Additionally, this is important for implementation of
'``catch``' clauses in high-level languages that support them.

For the purposes of the SSA form, the definition of the value returned
by the '``invoke``' instruction is deemed to occur on the edge from the
current block to the "normal" label. If the callee unwinds then no
return value is available.

Example:
""""""""

.. code-block:: llvm

      %retval = invoke i32 @Test(i32 15) to label %Continue
                  unwind label %TestCleanup              ; {i32}:retval set
      %retval = invoke coldcc i32 %Testfnptr(i32 15) to label %Continue
                  unwind label %TestCleanup              ; {i32}:retval set

.. _i_resume:

'``resume``' Instruction
^^^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      resume <type> <value>

Overview:
"""""""""

The '``resume``' instruction is a terminator instruction that has no
successors.

Arguments:
""""""""""

The '``resume``' instruction requires one argument, which must have the
same type as the result of any '``landingpad``' instruction in the same
function.

Semantics:
""""""""""

The '``resume``' instruction resumes propagation of an existing
(in-flight) exception whose unwinding was interrupted with a
:ref:`landingpad <i_landingpad>` instruction.

Example:
""""""""

.. code-block:: llvm

      resume { i8*, i32 } %exn

.. _i_unreachable:

'``unreachable``' Instruction
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      unreachable

Overview:
"""""""""

The '``unreachable``' instruction has no defined semantics. This
instruction is used to inform the optimizer that a particular portion of
the code is not reachable. This can be used to indicate that the code
after a no-return function cannot be reached, and other facts.

Semantics:
""""""""""

The '``unreachable``' instruction has no defined semantics.

.. _binaryops:

Binary Operations
-----------------

Binary operators are used to do most of the computation in a program.
They require two operands of the same type, execute an operation on
them, and produce a single value. The operands might represent multiple
data, as is the case with the :ref:`vector <t_vector>` data type. The
result value has the same type as its operands.

There are several different binary operators:

.. _i_add:

'``add``' Instruction
^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = add <ty> <op1>, <op2>          ; yields {ty}:result
      <result> = add nuw <ty> <op1>, <op2>      ; yields {ty}:result
      <result> = add nsw <ty> <op1>, <op2>      ; yields {ty}:result
      <result> = add nuw nsw <ty> <op1>, <op2>  ; yields {ty}:result

Overview:
"""""""""

The '``add``' instruction returns the sum of its two operands.

Arguments:
""""""""""

The two arguments to the '``add``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The value produced is the integer sum of the two operands.

If the sum has unsigned overflow, the result returned is the
mathematical result modulo 2\ :sup:`n`\ , where n is the bit width of
the result.

Because LLVM integers use a two's complement representation, this
instruction is appropriate for both signed and unsigned integers.

``nuw`` and ``nsw`` stand for "No Unsigned Wrap" and "No Signed Wrap",
respectively. If the ``nuw`` and/or ``nsw`` keywords are present, the
result value of the ``add`` is a :ref:`poison value <poisonvalues>` if
unsigned and/or signed overflow, respectively, occurs.

Example:
""""""""

.. code-block:: llvm

      <result> = add i32 4, %var          ; yields {i32}:result = 4 + %var

.. _i_fadd:

'``fadd``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = fadd [fast-math flags]* <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``fadd``' instruction returns the sum of its two operands.

Arguments:
""""""""""

The two arguments to the '``fadd``' instruction must be :ref:`floating
point <t_floating>` or :ref:`vector <t_vector>` of floating point values.
Both arguments must have identical types.

Semantics:
""""""""""

The value produced is the floating point sum of the two operands. This
instruction can also take any number of :ref:`fast-math flags <fastmath>`,
which are optimization hints to enable otherwise unsafe floating point
optimizations:

Example:
""""""""

.. code-block:: llvm

      <result> = fadd float 4.0, %var          ; yields {float}:result = 4.0 + %var

'``sub``' Instruction
^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = sub <ty> <op1>, <op2>          ; yields {ty}:result
      <result> = sub nuw <ty> <op1>, <op2>      ; yields {ty}:result
      <result> = sub nsw <ty> <op1>, <op2>      ; yields {ty}:result
      <result> = sub nuw nsw <ty> <op1>, <op2>  ; yields {ty}:result

Overview:
"""""""""

The '``sub``' instruction returns the difference of its two operands.

Note that the '``sub``' instruction is used to represent the '``neg``'
instruction present in most other intermediate representations.

Arguments:
""""""""""

The two arguments to the '``sub``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The value produced is the integer difference of the two operands.

If the difference has unsigned overflow, the result returned is the
mathematical result modulo 2\ :sup:`n`\ , where n is the bit width of
the result.

Because LLVM integers use a two's complement representation, this
instruction is appropriate for both signed and unsigned integers.

``nuw`` and ``nsw`` stand for "No Unsigned Wrap" and "No Signed Wrap",
respectively. If the ``nuw`` and/or ``nsw`` keywords are present, the
result value of the ``sub`` is a :ref:`poison value <poisonvalues>` if
unsigned and/or signed overflow, respectively, occurs.

Example:
""""""""

.. code-block:: llvm

      <result> = sub i32 4, %var          ; yields {i32}:result = 4 - %var
      <result> = sub i32 0, %val          ; yields {i32}:result = -%var

.. _i_fsub:

'``fsub``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = fsub [fast-math flags]* <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``fsub``' instruction returns the difference of its two operands.

Note that the '``fsub``' instruction is used to represent the '``fneg``'
instruction present in most other intermediate representations.

Arguments:
""""""""""

The two arguments to the '``fsub``' instruction must be :ref:`floating
point <t_floating>` or :ref:`vector <t_vector>` of floating point values.
Both arguments must have identical types.

Semantics:
""""""""""

The value produced is the floating point difference of the two operands.
This instruction can also take any number of :ref:`fast-math
flags <fastmath>`, which are optimization hints to enable otherwise
unsafe floating point optimizations:

Example:
""""""""

.. code-block:: llvm

      <result> = fsub float 4.0, %var           ; yields {float}:result = 4.0 - %var
      <result> = fsub float -0.0, %val          ; yields {float}:result = -%var

'``mul``' Instruction
^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = mul <ty> <op1>, <op2>          ; yields {ty}:result
      <result> = mul nuw <ty> <op1>, <op2>      ; yields {ty}:result
      <result> = mul nsw <ty> <op1>, <op2>      ; yields {ty}:result
      <result> = mul nuw nsw <ty> <op1>, <op2>  ; yields {ty}:result

Overview:
"""""""""

The '``mul``' instruction returns the product of its two operands.

Arguments:
""""""""""

The two arguments to the '``mul``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The value produced is the integer product of the two operands.

If the result of the multiplication has unsigned overflow, the result
returned is the mathematical result modulo 2\ :sup:`n`\ , where n is the
bit width of the result.

Because LLVM integers use a two's complement representation, and the
result is the same width as the operands, this instruction returns the
correct result for both signed and unsigned integers. If a full product
(e.g. ``i32`` * ``i32`` -> ``i64``) is needed, the operands should be
sign-extended or zero-extended as appropriate to the width of the full
product.

``nuw`` and ``nsw`` stand for "No Unsigned Wrap" and "No Signed Wrap",
respectively. If the ``nuw`` and/or ``nsw`` keywords are present, the
result value of the ``mul`` is a :ref:`poison value <poisonvalues>` if
unsigned and/or signed overflow, respectively, occurs.

Example:
""""""""

.. code-block:: llvm

      <result> = mul i32 4, %var          ; yields {i32}:result = 4 * %var

.. _i_fmul:

'``fmul``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = fmul [fast-math flags]* <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``fmul``' instruction returns the product of its two operands.

Arguments:
""""""""""

The two arguments to the '``fmul``' instruction must be :ref:`floating
point <t_floating>` or :ref:`vector <t_vector>` of floating point values.
Both arguments must have identical types.

Semantics:
""""""""""

The value produced is the floating point product of the two operands.
This instruction can also take any number of :ref:`fast-math
flags <fastmath>`, which are optimization hints to enable otherwise
unsafe floating point optimizations:

Example:
""""""""

.. code-block:: llvm

      <result> = fmul float 4.0, %var          ; yields {float}:result = 4.0 * %var

'``udiv``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = udiv <ty> <op1>, <op2>         ; yields {ty}:result
      <result> = udiv exact <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``udiv``' instruction returns the quotient of its two operands.

Arguments:
""""""""""

The two arguments to the '``udiv``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The value produced is the unsigned integer quotient of the two operands.

Note that unsigned integer division and signed integer division are
distinct operations; for signed integer division, use '``sdiv``'.

Division by zero leads to undefined behavior.

If the ``exact`` keyword is present, the result value of the ``udiv`` is
a :ref:`poison value <poisonvalues>` if %op1 is not a multiple of %op2 (as
such, "((a udiv exact b) mul b) == a").

Example:
""""""""

.. code-block:: llvm

      <result> = udiv i32 4, %var          ; yields {i32}:result = 4 / %var

'``sdiv``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = sdiv <ty> <op1>, <op2>         ; yields {ty}:result
      <result> = sdiv exact <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``sdiv``' instruction returns the quotient of its two operands.

Arguments:
""""""""""

The two arguments to the '``sdiv``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The value produced is the signed integer quotient of the two operands
rounded towards zero.

Note that signed integer division and unsigned integer division are
distinct operations; for unsigned integer division, use '``udiv``'.

Division by zero leads to undefined behavior. Overflow also leads to
undefined behavior; this is a rare case, but can occur, for example, by
doing a 32-bit division of -2147483648 by -1.

If the ``exact`` keyword is present, the result value of the ``sdiv`` is
a :ref:`poison value <poisonvalues>` if the result would be rounded.

Example:
""""""""

.. code-block:: llvm

      <result> = sdiv i32 4, %var          ; yields {i32}:result = 4 / %var

.. _i_fdiv:

'``fdiv``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = fdiv [fast-math flags]* <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``fdiv``' instruction returns the quotient of its two operands.

Arguments:
""""""""""

The two arguments to the '``fdiv``' instruction must be :ref:`floating
point <t_floating>` or :ref:`vector <t_vector>` of floating point values.
Both arguments must have identical types.

Semantics:
""""""""""

The value produced is the floating point quotient of the two operands.
This instruction can also take any number of :ref:`fast-math
flags <fastmath>`, which are optimization hints to enable otherwise
unsafe floating point optimizations:

Example:
""""""""

.. code-block:: llvm

      <result> = fdiv float 4.0, %var          ; yields {float}:result = 4.0 / %var

'``urem``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = urem <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``urem``' instruction returns the remainder from the unsigned
division of its two arguments.

Arguments:
""""""""""

The two arguments to the '``urem``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

This instruction returns the unsigned integer *remainder* of a division.
This instruction always performs an unsigned division to get the
remainder.

Note that unsigned integer remainder and signed integer remainder are
distinct operations; for signed integer remainder, use '``srem``'.

Taking the remainder of a division by zero leads to undefined behavior.

Example:
""""""""

.. code-block:: llvm

      <result> = urem i32 4, %var          ; yields {i32}:result = 4 % %var

'``srem``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = srem <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``srem``' instruction returns the remainder from the signed
division of its two operands. This instruction can also take
:ref:`vector <t_vector>` versions of the values in which case the elements
must be integers.

Arguments:
""""""""""

The two arguments to the '``srem``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

This instruction returns the *remainder* of a division (where the result
is either zero or has the same sign as the dividend, ``op1``), not the
*modulo* operator (where the result is either zero or has the same sign
as the divisor, ``op2``) of a value. For more information about the
difference, see `The Math
Forum <http://mathforum.org/dr.math/problems/anne.4.28.99.html>`_. For a
table of how this is implemented in various languages, please see
`Wikipedia: modulo
operation <http://en.wikipedia.org/wiki/Modulo_operation>`_.

Note that signed integer remainder and unsigned integer remainder are
distinct operations; for unsigned integer remainder, use '``urem``'.

Taking the remainder of a division by zero leads to undefined behavior.
Overflow also leads to undefined behavior; this is a rare case, but can
occur, for example, by taking the remainder of a 32-bit division of
-2147483648 by -1. (The remainder doesn't actually overflow, but this
rule lets srem be implemented using instructions that return both the
result of the division and the remainder.)

Example:
""""""""

.. code-block:: llvm

      <result> = srem i32 4, %var          ; yields {i32}:result = 4 % %var

.. _i_frem:

'``frem``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = frem [fast-math flags]* <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``frem``' instruction returns the remainder from the division of
its two operands.

Arguments:
""""""""""

The two arguments to the '``frem``' instruction must be :ref:`floating
point <t_floating>` or :ref:`vector <t_vector>` of floating point values.
Both arguments must have identical types.

Semantics:
""""""""""

This instruction returns the *remainder* of a division. The remainder
has the same sign as the dividend. This instruction can also take any
number of :ref:`fast-math flags <fastmath>`, which are optimization hints
to enable otherwise unsafe floating point optimizations:

Example:
""""""""

.. code-block:: llvm

      <result> = frem float 4.0, %var          ; yields {float}:result = 4.0 % %var

.. _bitwiseops:

Bitwise Binary Operations
-------------------------

Bitwise binary operators are used to do various forms of bit-twiddling
in a program. They are generally very efficient instructions and can
commonly be strength reduced from other instructions. They require two
operands of the same type, execute an operation on them, and produce a
single value. The resulting value is the same type as its operands.

'``shl``' Instruction
^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = shl <ty> <op1>, <op2>           ; yields {ty}:result
      <result> = shl nuw <ty> <op1>, <op2>       ; yields {ty}:result
      <result> = shl nsw <ty> <op1>, <op2>       ; yields {ty}:result
      <result> = shl nuw nsw <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``shl``' instruction returns the first operand shifted to the left
a specified number of bits.

Arguments:
""""""""""

Both arguments to the '``shl``' instruction must be the same
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer type.
'``op2``' is treated as an unsigned value.

Semantics:
""""""""""

The value produced is ``op1`` \* 2\ :sup:`op2` mod 2\ :sup:`n`,
where ``n`` is the width of the result. If ``op2`` is (statically or
dynamically) negative or equal to or larger than the number of bits in
``op1``, the result is undefined. If the arguments are vectors, each
vector element of ``op1`` is shifted by the corresponding shift amount
in ``op2``.

If the ``nuw`` keyword is present, then the shift produces a :ref:`poison
value <poisonvalues>` if it shifts out any non-zero bits. If the
``nsw`` keyword is present, then the shift produces a :ref:`poison
value <poisonvalues>` if it shifts out any bits that disagree with the
resultant sign bit. As such, NUW/NSW have the same semantics as they
would if the shift were expressed as a mul instruction with the same
nsw/nuw bits in (mul %op1, (shl 1, %op2)).

Example:
""""""""

.. code-block:: llvm

      <result> = shl i32 4, %var   ; yields {i32}: 4 << %var
      <result> = shl i32 4, 2      ; yields {i32}: 16
      <result> = shl i32 1, 10     ; yields {i32}: 1024
      <result> = shl i32 1, 32     ; undefined
      <result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2>   ; yields: result=<2 x i32> < i32 2, i32 4>

'``lshr``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = lshr <ty> <op1>, <op2>         ; yields {ty}:result
      <result> = lshr exact <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``lshr``' instruction (logical shift right) returns the first
operand shifted to the right a specified number of bits with zero fill.

Arguments:
""""""""""

Both arguments to the '``lshr``' instruction must be the same
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer type.
'``op2``' is treated as an unsigned value.

Semantics:
""""""""""

This instruction always performs a logical shift right operation. The
most significant bits of the result will be filled with zero bits after
the shift. If ``op2`` is (statically or dynamically) equal to or larger
than the number of bits in ``op1``, the result is undefined. If the
arguments are vectors, each vector element of ``op1`` is shifted by the
corresponding shift amount in ``op2``.

If the ``exact`` keyword is present, the result value of the ``lshr`` is
a :ref:`poison value <poisonvalues>` if any of the bits shifted out are
non-zero.

Example:
""""""""

.. code-block:: llvm

      <result> = lshr i32 4, 1   ; yields {i32}:result = 2
      <result> = lshr i32 4, 2   ; yields {i32}:result = 1
      <result> = lshr i8  4, 3   ; yields {i8}:result = 0
      <result> = lshr i8 -2, 1   ; yields {i8}:result = 0x7FFFFFFF 
      <result> = lshr i32 1, 32  ; undefined
      <result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2>   ; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1>

'``ashr``' Instruction
^^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = ashr <ty> <op1>, <op2>         ; yields {ty}:result
      <result> = ashr exact <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``ashr``' instruction (arithmetic shift right) returns the first
operand shifted to the right a specified number of bits with sign
extension.

Arguments:
""""""""""

Both arguments to the '``ashr``' instruction must be the same
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer type.
'``op2``' is treated as an unsigned value.

Semantics:
""""""""""

This instruction always performs an arithmetic shift right operation,
The most significant bits of the result will be filled with the sign bit
of ``op1``. If ``op2`` is (statically or dynamically) equal to or larger
than the number of bits in ``op1``, the result is undefined. If the
arguments are vectors, each vector element of ``op1`` is shifted by the
corresponding shift amount in ``op2``.

If the ``exact`` keyword is present, the result value of the ``ashr`` is
a :ref:`poison value <poisonvalues>` if any of the bits shifted out are
non-zero.

Example:
""""""""

.. code-block:: llvm

      <result> = ashr i32 4, 1   ; yields {i32}:result = 2
      <result> = ashr i32 4, 2   ; yields {i32}:result = 1
      <result> = ashr i8  4, 3   ; yields {i8}:result = 0
      <result> = ashr i8 -2, 1   ; yields {i8}:result = -1
      <result> = ashr i32 1, 32  ; undefined
      <result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3>   ; yields: result=<2 x i32> < i32 -1, i32 0>

'``and``' Instruction
^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = and <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``and``' instruction returns the bitwise logical and of its two
operands.

Arguments:
""""""""""

The two arguments to the '``and``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The truth table used for the '``and``' instruction is:

+-----+-----+-----+
| In0 | In1 | Out |
+-----+-----+-----+
|   0 |   0 |   0 |
+-----+-----+-----+
|   0 |   1 |   0 |
+-----+-----+-----+
|   1 |   0 |   0 |
+-----+-----+-----+
|   1 |   1 |   1 |
+-----+-----+-----+

Example:
""""""""

.. code-block:: llvm

      <result> = and i32 4, %var         ; yields {i32}:result = 4 & %var
      <result> = and i32 15, 40          ; yields {i32}:result = 8
      <result> = and i32 4, 8            ; yields {i32}:result = 0

'``or``' Instruction
^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = or <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``or``' instruction returns the bitwise logical inclusive or of its
two operands.

Arguments:
""""""""""

The two arguments to the '``or``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The truth table used for the '``or``' instruction is:

+-----+-----+-----+
| In0 | In1 | Out |
+-----+-----+-----+
|   0 |   0 |   0 |
+-----+-----+-----+
|   0 |   1 |   1 |
+-----+-----+-----+
|   1 |   0 |   1 |
+-----+-----+-----+
|   1 |   1 |   1 |
+-----+-----+-----+

Example:
""""""""

::

      <result> = or i32 4, %var         ; yields {i32}:result = 4 | %var
      <result> = or i32 15, 40          ; yields {i32}:result = 47
      <result> = or i32 4, 8            ; yields {i32}:result = 12

'``xor``' Instruction
^^^^^^^^^^^^^^^^^^^^^

Syntax:
"""""""

::

      <result> = xor <ty> <op1>, <op2>   ; yields {ty}:result

Overview:
"""""""""

The '``xor``' instruction returns the bitwise logical exclusive or of
its two operands. The ``xor`` is used to implement the "one's
complement" operation, which is the "~" operator in C.

Arguments:
""""""""""

The two arguments to the '``xor``' instruction must be
:ref:`integer <t_integer>` or :ref:`vector <t_vector>` of integer values. Both
arguments must have identical types.

Semantics:
""""""""""

The truth table used for the '``xor``' instruction is:

+-----+-----+-----+
| In0 | In1 | Out |
+-----+-----+-----+
|   0 |   0 |   0 |
+-----+-----+-----+
|   0 |   1 |   1 |
+-----+-----+-----+
|   1 |   0 |   1 |
+-----+-----+-----+
|   1 |   1 |   0 |
+-----+-----+-----+

Example:
""""""""

.. code-block:: llvm

      <result> = xor i32 4, %var         ; yields {i32}:result = 4 ^ %var
      <result> = xor i32 15, 40          ; yields {i32}:result = 39
      <result> = xor i32 4, 8            ; yields {i32}:result = 12